Post clean treatment

Abstract

A composition for removal of chemical residues from metal or dielectric surfaces or for chemical mechanical polishing of a copper surface is an aqueous solution with a pH between about 3.5 and about 7. The composition contains a monofunctional, difunctional or trifunctional organic acid and a buffering amount of a quaternary amine, ammonium hydroxide, hydroxylamine, hydroxylamine salt, hydrazine or hydrazine salt base. A method in accordance with the invention for removal of chemical residues from a metal or dielectric surface comprises contacting the metal or dielectric surface with the above composition for a time sufficient to remove the chemical residues. A method in accordance with the invention for chemical mechanical polishing of a copper surface comprises applying the above composition to the copper surface, and polishing the surface in the presence of the composition.

What is claimed is: 
     
       1. A method for removal of chemical residues from a metal or dielectric surface, which comprises contacting the metal or dielectric surface with a composition which comprises an aqueous solution with a pH between about 4 and about 6 and containing: (a) a monofunctional, difunctional or trifunctional organic acid selected from the group consisting of formic, acetic, propionic, n-butyric, benzoic, ascorbic, gluconic, malic, malonic, oxalic, succinic, tartaric, citric and gallic acids; and   (b) a buffering amount of hydroxylamine, for a time sufficient to remove the chemical residues.   
     
     
       2. The method of claim 1 in which the pH of the aqueous composition is adjusted with a buffering amount of a quaternary amine, ammonium hydroxide, hydroxylamine, hydroxylamine salt, hydrazine or hydrazine salt base. 
     
     
       3. The method of claim 1 in which the aqueous composition includes a chelation agent which will complex with transition metal ions and mobile ions. 
     
     
       4. The method of claim 3 in which the chelation agent is ethylene diamine tetraacetic acid, an oxime, 8-hydroxy quinoline, a polyalkylenepolyamine or a crown ether. 
     
     
       5. The method of claim 1 in which the aqueous composition includes an oxidizing agent which will maintain metal film oxide layers. 
     
     
       6. The method of claim 5 in which the oxidizing agent comprises ammonium peroxydisulfate, peracetic acid, urea hydroperoxide, sodium percarbonate or sodium perborate. 
     
     
       7. A method for chemical mechanical polishing of a copper surface which comprises applying a composition which comprises an aqueous solution with a pH between about 4 and about 6 and containing: (a) a monofunctional, difunctional or trifunctional organic acid selected from the group consisting of formic, acetic, propionic, n-butyric, benzoic, ascorbic, gluconic, malic, malonic, oxalic, succinic, tartaric, citric and gallic acids; and   (b) a buffering amount of hydroxylamine to the copper surface, and polishing the surface in the presence of the composition.   
     
     
       8. The method of claim 7 in which the pH of the aqueous composition is additionally adjusted with a buffering amount of a quatenary amine, ammonium hydroxide, hydroxylamine salt, hydrazine or hydrazine salt base. 
     
     
       9. The method of claim 7 in which the aqueous composition includes a chelation agent which will complex with transition metal ions and mobile ions. 
     
     
       10. The method claim 9 in which the chelation agent is ethylene diamine tetraacetic acid, an oxime, 8-hydroxy quinoline, a polyalkylenepolyamine or a crown ether. 
     
     
       11. The method of claim 7 in which the aqueous composition includes an oxidizing agent which will maintain metal film oxide layers. 
     
     
       12. The method of claim 11 in which the oxidizing agent comprises ammonium peroxydisulfate, peracetic acid, urea hydroperoxide, sodium percarbonate or sodium perborate.